This invention relates generally to expansion valves for refrigeration systems and particularly to an expansion valve having an improved strainer system at the inlet of the valve.
Concern about ozone depletion has led to the replacement of refrigerants formerly commonly used in commercial refrigeration systems, such as in supermarkets. These refrigerants are therefore being replaced with other refrigerants such as R-22. This refrigerant has a relatively high enthalphy and therefore uses a smaller port sizing for the thermostatic valves. Accordingly, the valves are much more susceptible to dirt collection which is a problem.
Another problem with refrigeration systems which affects the ozone layer is external leakage at the valve connections. In order to cut down leakage problems soldered joints are being used in lieu of flared joints. With flared joints, a strainer assembly placed in the inlet fitting of an expansion valve can be removed and cleaned comparatively easily. Removal and replacement are considerably more difficult to accomplish with soldered joints which must be unsoldered and resoldered, a task frequently made more difficult because of poor access.
These disadvantages are overcome with the present expansion valve strainer system in a manner not revealed in the known prior art.